Talk:Andromeda–Milky Way collision

Survival

This article doesn't answer the question I came here to read about: will our descendants survive? Not on Earth (too hot), but assuming migration through the Milky Way by that time. Not by collisions with stars (improbable), but by encounters near enough to disturb the Oort cloud and similar objects throughout the galaxy, and rain asteroids on planets everywhere. Or is that realistic and/or documented? Art LaPella (talk) 02:51, 8 September 2017 (UTC)

You are asking whether our descendants might survive a galaxy merger in three to four billion years' time? (Billions, not millions, although millions of years are long enough.)

It is an interesting thought experiment. I'm going to say "no". But do ask your people to tell my people (or to come back and tell us know) if I am wrong.

As a side question, what do you think our descendants might look like in three to four billion years' time? And what kind of physical environment might they need? (Compare: what did our ancestors look like three to four billion years ago? Single-celled prokaryotes, archaea or something like the cyanobacteria, perhaps photosynthesising if you are lucky. And what was the Earth like then, in the Archaen? Radically different to today, and rather inhospitable for us.)

Would we even recognise them as our descendants, if they have evolved into beings of energy, or they have become human-mechanical cyborgs, or some silicon-based entity that is not particularly human at all. Species tend to last for several million years before something better comes along or the environment changes, but sometimes they can last for hundreds of millions if they remain competitive. Do you think that will apply to a fast-moving, adaptive, primate mammal species like us?

You also assume that our descendants will have migrated away from the Earth (as you say, they will probably need to have left home by that stage, because the Sun will have evolved away from the main sequence into a red giant, and personally I think they will need to move away to survive anything like that long, else an event such as a nearby supernova or a Snowball Earth climate could kill us all); but perhaps they will adapt to the physical conditions, or they won't care about them, or perhaps asbestos underwear will suffice.

Also note that this "event" will itself take place over many millions of years, and arguably (given that Andromeda is approaching the Milky Way at 100 km/s) has already started. More of a process than a one-off event. When will you know that it has been completed? Given our state of knowledge, a close encounter is inevitable, but we are not yet sure it will be a full merger: we might end up with disruption and tidal tails like the Antennae Galaxies or the Mice Galaxies.

As John Maynard Keynes said, in the long run, we are all dead. 213.205.240.202 (talk) 16:55, 19 September 2018 (UTC)

Thank you. I think I can summarize that as "undocumented". As for future evolution, I would presume anyone capable of galactic space travel would be capable of genetic engineering. We'll either be whatever we want to be, or else we'll be replaced by what escaped out of our control. In the longer run, there are other galaxies; after that is the heat death of the universe. Art LaPella (talk) 17:50, 19 September 2018 (UTC)

Speed of movement towards does not match with other sites on Wikipedia

Example: The article about "Future of an expanding universe" does state another speed of movement of the 2 galaxies coming closer. Please check that. E.g. if you take the time 4*10^9 years and the distance 2,5*10^6 light years as given, then you can compute the velocity. Would of course be very dubious if you computed this way. In(approximately)4.696 billion years, our galaxy will collide into another galaxy called Andromeda. — Preceding unsigned comment added by 2600:8800:1300:25b:e86e:add0:b8d1:3062 (talk • contribs)

I reverted 4.696 because your calculation is Wikipedia:Original research. The first two references say 4 billion, the third says 5 billion and the fourth is offline. It may seem like a simple time=distance/speed problem, but you yourself said that would be very dubious (for one thing, gravity accelerates the galaxies as they get close. For another, there's a significant sideways velocity component.) But I agree this article should match Future of an expanding universe#Milky Way Galaxy and the Andromeda Galaxy merge into one better. Art LaPella (talk) 04:25, 17 September 2018 (UTC)

Milkomeda? No Way

Sorry but i can't take giving the collision a name that would better fit in Disney World for serious. (Via)Lacteandromedae, Andromelactea, ... please? — Preceding unsigned comment added by KnightOfTheNite (talk • contribs) 09:40, 17 September 2019 (UTC)

Propose deletion of nonsense in Black Hole section

The black hole collisions section contains incorrect statements, with links to non-existent references. These are currently references 11 and 12. I recommend deleting the text: "As of 2006, simulations indicated that the Sun might be brought near the centre of the combined galaxy, potentially coming near one of the black holes before being ejected entirely out of the galaxy.[11] Alternatively, the Sun might approach one of the black holes a bit closer and be torn apart by its gravity. Parts of the former Sun would be pulled into the black hole.[12]" Jpfleblanc (talk) 14:13, 14 January 2020 (UTC)

Page name contains a long hyphen

The page name contains a long hyphen (don't know the official term) rather than a regular hyphen. Thus when the url is copied then pasted, it converts to https://en.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_collision. Was this deliberate? (I could not figure out how to change it.)